#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "parser.h"

#define MIN(a, b) (a > b ? b : a)

#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
#define mix(a,b,c)                  \
{                                   \
  a -= c;  a ^= rot(c, 4);  c += b; \
  b -= a;  b ^= rot(a, 6);  a += c; \
  c -= b;  c ^= rot(b, 8);  b += a; \
  a -= c;  a ^= rot(c,16);  c += b; \
  b -= a;  b ^= rot(a,19);  a += c; \
  c -= b;  c ^= rot(b, 4);  b += a; \
}

#define final(a,b,c)      \
{                         \
  c ^= b; c -= rot(b,14); \
  a ^= c; a -= rot(c,11); \
  b ^= a; b -= rot(a,25); \
  c ^= b; c -= rot(b,16); \
  a ^= c; a -= rot(c,4);  \
  b ^= a; b -= rot(a,14); \
  c ^= b; c -= rot(b,24); \
}

static const uint16_t crc16tab[256]= {
    0x0000,0x1021,0x2042,0x3063,0x4084,0x50a5,0x60c6,0x70e7,
    0x8108,0x9129,0xa14a,0xb16b,0xc18c,0xd1ad,0xe1ce,0xf1ef,
    0x1231,0x0210,0x3273,0x2252,0x52b5,0x4294,0x72f7,0x62d6,
    0x9339,0x8318,0xb37b,0xa35a,0xd3bd,0xc39c,0xf3ff,0xe3de,
    0x2462,0x3443,0x0420,0x1401,0x64e6,0x74c7,0x44a4,0x5485,
    0xa56a,0xb54b,0x8528,0x9509,0xe5ee,0xf5cf,0xc5ac,0xd58d,
    0x3653,0x2672,0x1611,0x0630,0x76d7,0x66f6,0x5695,0x46b4,
    0xb75b,0xa77a,0x9719,0x8738,0xf7df,0xe7fe,0xd79d,0xc7bc,
    0x48c4,0x58e5,0x6886,0x78a7,0x0840,0x1861,0x2802,0x3823,
    0xc9cc,0xd9ed,0xe98e,0xf9af,0x8948,0x9969,0xa90a,0xb92b,
    0x5af5,0x4ad4,0x7ab7,0x6a96,0x1a71,0x0a50,0x3a33,0x2a12,
    0xdbfd,0xcbdc,0xfbbf,0xeb9e,0x9b79,0x8b58,0xbb3b,0xab1a,
    0x6ca6,0x7c87,0x4ce4,0x5cc5,0x2c22,0x3c03,0x0c60,0x1c41,
    0xedae,0xfd8f,0xcdec,0xddcd,0xad2a,0xbd0b,0x8d68,0x9d49,
    0x7e97,0x6eb6,0x5ed5,0x4ef4,0x3e13,0x2e32,0x1e51,0x0e70,
    0xff9f,0xefbe,0xdfdd,0xcffc,0xbf1b,0xaf3a,0x9f59,0x8f78,
    0x9188,0x81a9,0xb1ca,0xa1eb,0xd10c,0xc12d,0xf14e,0xe16f,
    0x1080,0x00a1,0x30c2,0x20e3,0x5004,0x4025,0x7046,0x6067,
    0x83b9,0x9398,0xa3fb,0xb3da,0xc33d,0xd31c,0xe37f,0xf35e,
    0x02b1,0x1290,0x22f3,0x32d2,0x4235,0x5214,0x6277,0x7256,
    0xb5ea,0xa5cb,0x95a8,0x8589,0xf56e,0xe54f,0xd52c,0xc50d,
    0x34e2,0x24c3,0x14a0,0x0481,0x7466,0x6447,0x5424,0x4405,
    0xa7db,0xb7fa,0x8799,0x97b8,0xe75f,0xf77e,0xc71d,0xd73c,
    0x26d3,0x36f2,0x0691,0x16b0,0x6657,0x7676,0x4615,0x5634,
    0xd94c,0xc96d,0xf90e,0xe92f,0x99c8,0x89e9,0xb98a,0xa9ab,
    0x5844,0x4865,0x7806,0x6827,0x18c0,0x08e1,0x3882,0x28a3,
    0xcb7d,0xdb5c,0xeb3f,0xfb1e,0x8bf9,0x9bd8,0xabbb,0xbb9a,
    0x4a75,0x5a54,0x6a37,0x7a16,0x0af1,0x1ad0,0x2ab3,0x3a92,
    0xfd2e,0xed0f,0xdd6c,0xcd4d,0xbdaa,0xad8b,0x9de8,0x8dc9,
    0x7c26,0x6c07,0x5c64,0x4c45,0x3ca2,0x2c83,0x1ce0,0x0cc1,
    0xef1f,0xff3e,0xcf5d,0xdf7c,0xaf9b,0xbfba,0x8fd9,0x9ff8,
    0x6e17,0x7e36,0x4e55,0x5e74,0x2e93,0x3eb2,0x0ed1,0x1ef0
};

uint32_t lookup3_hash(const char *key)
{
    uint32_t a,b,c;

    uint32_t length = strlen(key);
    /* Set up the internal state */
    a = b = c = 0xdeadbeef + length;

    const uint8_t *k = (const uint8_t *)key;

    while (length > 12) {
        a += k[0];
        a += ((uint32_t)k[1])<<8;
        a += ((uint32_t)k[2])<<16;
        a += ((uint32_t)k[3])<<24;
        b += k[4];
        b += ((uint32_t)k[5])<<8;
        b += ((uint32_t)k[6])<<16;
        b += ((uint32_t)k[7])<<24;
        c += k[8];
        c += ((uint32_t)k[9])<<8;
        c += ((uint32_t)k[10])<<16;
        c += ((uint32_t)k[11])<<24;
        mix(a,b,c);
        length -= 12;
        k += 12;
    }

    switch(length) {
        case 12: c+=((uint32_t)k[11])<<24;
        case 11: c+=((uint32_t)k[10])<<16;
        case 10: c+=((uint32_t)k[9])<<8;
        case 9 : c+=k[8];
        case 8 : b+=((uint32_t)k[7])<<24;
        case 7 : b+=((uint32_t)k[6])<<16;
        case 6 : b+=((uint32_t)k[5])<<8;
        case 5 : b+=k[4];
        case 4 : a+=((uint32_t)k[3])<<24;
        case 3 : a+=((uint32_t)k[2])<<16;
        case 2 : a+=((uint32_t)k[1])<<8;
        case 1 : a+=k[0]; break;
        case 0 : return c;
        }

    final(a,b,c);
    return c;
}

uint16_t crc16(struct pos_array *pos)
{
    uint16_t crc = 0;
    const struct pos *p;
    uint8_t *s;
    int h, c, len;

    for (h = 0; h < pos->pos_len; h++) {
        p = &pos->items[h];
        len = p->len;
        s = p->str;

        for (c = 0; c < len; c++) {
            crc = (crc << 8) ^ crc16tab[((crc >> 8) ^ *s++) & 0x00FF];
        }
    }
    return crc;
}
